High spatiotemporal resolution analyses of dynamics of synaptic vesicle proteins

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H02526
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 46010:Neuroscience-general-related
• Research Institution: Kyoto University
• Principal Investigator: Hirano Tomoo 京都大学, 理学研究科, 教授 (50181178)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: シナプス / 神経伝達物質 / エキソサイトーシス / エンドサイトーシス / ライブイメージング / 蛍光タンパク質

Outline of Final Research Achievements

Exocytosis and endocytosis of a synaptic vesicle protein in and around a presynaptic active zone were studied by live-cell fluorescence imaging of synaptophysin (syp) tagged with a pH-sensitive fluorescent protein super-ecliptic phluorin (SEP) using a novel visualization technique. Syp-SEP which had moved to the cell membrane diffused after the exocytosis. Synchronous exocytosis occurring immediately after the electrical stimulation took place at several sites within an active zone, whereas asynchronous exocytosis occurring tens to hundreds milliseconds after the stimulation took a place at different sites. We also recorded endocytosis of syp-SEP occurring in the periphery of active zone. The endocytosis occurring within a second after the stimulation and that occurring later showed different characteristics such as temperature-dependence.

Free Research Field

分子細胞神経科学

Academic Significance and Societal Importance of the Research Achievements

本研究では、未解明の問題が多く残されているシナプス前部からのシナプス小胞の開口放出と、シナプス小胞膜タンパク質の細胞内への回収過程の詳細を明らかにすることに寄与する実験方法を確立し、それを活用することにより新知見を得た。これらの研究成果は、脳・神経系における情報伝達の分子・細胞機構の解明に貢献するとともに、将来的には幾多の神経・精神疾患の発症メカニズムの理解向上を介して、それらの予防・治療方法の改善に寄与することが期待できる。